Typewriter



Oct. 20, 1936. D. P. ROWLAND ET AL TYPEWRITER Filed Feb. 25, 1935 Sheets-Sheet 1 INVENTO s R 1' 6) /3@%u/afid BY a man carer W mu s Oct. 20, 1936. D. P. ROWLAND ET AL TYPEWRITER 4 Sheets-Sheet 2 Filed Feb. 23, 1933 f nal/Ill! INVENTORS Dar cymondG .g I

Oct. 20, 1936. D. P, ROWLAND ET AL 2,057,981

TYPEWRITER Filed Feb. 23-, '1933 4 Sheets-Sheet 3 INVENTOR s i Paw/and x BY Payma'flda-Bawep M WZLW a ATTORNEYS Oct. 20, 1936. D. P. ROWLAND ET AL TYPEWRITER Filed Feb. 25, 1953 4 h s-Sheet 4 INVENTORS Dzu/ghf P Pow/and dGiBawer 5g BY M ATT NEYS %.te1rtte @ct. Q, 193

T E f 'ryrnwurrna" Dwight P.

Rowland and Raymond G. Bower,

Detroit, Mich., assignors to Burroughs Adding Machine Company, Detroit, Mich., a corporation of Michigan Application February 23, 1933, Serial No. 657,992 24 Claims. (Cl. 197-'138) This invention relates to typewriters and it has '10 after which the feed rolls are moved against the platen, the rolls usually being yieldably urged against the platen for holding the work sheets in feeding relation thereto. It is very important that each of the rolls engage the platen with the 1 same uniform pressure and that the rolls be maintained in true alignment. Otherwise wrinkling and distortion of the paper or work sheets will occur with consequent wasteful results. The.

maintenance of these conditions is especially important where thework is in the form of V stencil paper which is usually frail and waxy and easily wrinkled, in the case of very thin copy paper which is used very extensively, and also where several sheets of paper separated by carbons are used.

One of the objects of the present invention is to provide an improved feed roll mechanism that will solve the difiiculties above mentioned.

A more particular object is to provide an improved feed roll mechanism so arranged that the feed rolls will each engage the platen with uniform pressure and be maintained accurately in alignment. l

Another difficulty that is encountered with typewriters is in connection with the paper apron or guide thatis located beneath the platen to guide the work sheets about the platen as they are inserted between the latter and the feed rolls.

This paper apron is generally moved away from the platen as the feed rollsare moved away and it is then reengaged'or moved upwardly toward the platen as the feed rolls are released. One of the difliculties encountered is that, whilethe papers maybe positioned accurately when the feed rolls are out of engagement with the platen, the

paper may move slightly as the feed rolls move toward the platen with the result that,'when the feed rolls grip the papers, they are not in ab-. solutely accurate position. Separate holding devices have been .provided for overcoming, this difficulty but the present invention is directed for a solution of this difliculty without the use;

. of such 'cial devices.

in released condition; 7

invention is to provide an improved paper apron arrangement.

A more particular object is; to provide a paper apron or shield that will not only guide the papers about the platen, but which will hold them in position while the feed rolls are being moved to feeding position.

A further object is to provide mechanism for the carrying out of the foregoing objects and features which is simple in construction, is quite 1 durable and lasting, is more efficient in operation insuring increased accuracy in work feed, and is composed of parts which are readily accessible and which maybe easily and quickly adjusted and operated. 15

Other objects and advantages will become ap-' parent as this description progresses and by reference to the drawings wherein,

Figure 1 is a front perspective view of a feed roll mechanism embodying the invention, the

platen being indicated in dotted lines, and certain of the feed roll mechanism parts being broken away to more clearly illustrate details thereof;

.. Fig. 2 is a perspective view of one of the yokes' used in the feed roll mechanism; 5

Fig; 3 is an enlarged right end elevational View, partially in section, of the structure shown ,in Fig. 1, the feed roll mechanism being shown in operative feedingrelation withrespect to the Fig. 4 is a view similar to Fig. 3 except slightly reduced and illustrating the feed roll mechanism platen with the right sideframe removed; 30

Fig. 5 is an enlarged fragmental sectional view through sin-intermediate portion of the feed roll 35 mechanism showing how the paper apron is limited in its downward movement;

Fig. 6 is a front perspective view similar to Fig. 101 a modified form of feed roll mechanism;

Fig. 7 is an enlarged transverse, right-side 40 sectional elevation of the structure shown in Fig. 6; I

Fig. 8 is a fragmentary view, partially in section, of individual spring units associated with the feed roll mechanism of Fig. 1;

Fig. 9 is an enlarged right end elevational view, partially in section, of a) modified form of paper apron; and v Fig. 10 is a view similar-to Fig. 9 but reduced and illustrating the feed roll mechanism in its 50 inclusive, portions of a carriage have been shown Accordi gly, another important objectof the including a platen l rotatably supported by side 55 customed position beneath the platen and cooperates with the latter.

Feed roll mechanism The feed roll mechanism (Fig. 1) includes a rearfeed roll I0, and a plurality of front feed rolls These feed rolls are carried by rocker arms- |2 which are supported by yoke arms |3 that are urged counterclockwise by springs M (Fig. 1) to urge the feed rolls into engagement with the platen. The feed rolls may be moved out of engagement with the platen by means of an operating shaft l5 which can be rocked by means of afinger piece It;

The rear feed roll in is relatively large and its length is only slightly less than the length of the platen. It is rotatably supported upon a single shaft carried by the rocker arms |2 of which there are two, one at each end of the feed r'oll mechanism. The shaft 20 is made relatively large and rigid so that it will resist flexing or bending and thereby maintain the rear feed roll in uniform engagement with the platen when in paper feeding position. By making the rear feed roll of the length illustrated it grips the paper for its entire length, it tends to exert a uniform pressure on the paper, and it has a tendency to move the paper evenly as it is being fed into the machine.

The front feed rolls I of which four are shown in Fig. 1, are rotatably supported upon a single shaft 2| which, in turn, is rotatably supported at its ends in the rocker arms i2. The mounting of all the front feed rolls on a single'shaft tends to keep the rolls in accurate axial alignment with one another. This is a decided advantage as compared with a construction where the 'feed rolls are mounted separately or in groups. A single feed roll at the front extending for the full length of the mechanism is not desirable because the front feed rolls must be of such small diameter that the size of the supporting shaft would have to be too small to give the necessary rigidity. But, by using a plurality of feed rolls, a single rigid supporting shaft 2| may be employed, together with centrally-located bearingsto give the necessary rigidity to the single shaft.

The rocker arms 2' which Support both the front and the rear feed roll shafts are provided with hubs or collars 22 near their centers which are mounted on short shafts or pins 23 carried by the yoke arms or supports l3 which are journaled on the operating rock shaft IS. The hubs 22 provide a wide bearing for the rocker arms and promote rigidity.

The yokes. l3 which support the rocker arms l2 are of novel construction and possess a number of advantages as follows: These yokes comprise two side plates 24 and 25 (Fig. 2) joined by a bottom or bridge section 28 which holds the two sides together in spaced relation. When the yokes are mounted on the operating rock shaft IS the spaced relation of the side. arms provides a support having a relatively broad base which tends to resist twisting stresses, side thrusts, and which, in general provides a rigid and strong support.-

By having a yoke which affords support for both ends of a pin or short shaft 23, it is possible to employ a hub or collar 22 on the rocker arms and a much more stable support is provided for the rocker arm than if the rocker arm itself were simply iournaled on the pivot pin.

Both of the side arms 24 and 25 of the yokes are provided with hooked projections 21 for receiving the springs l4 that urge the feed rolls toward the platen. This is an important advantage in that it assists in making. the yokes interchangeable, that is, they can be positioned to the right or left, as shown for the end yokes in Fig. 1, and the springs can be connected to either of the side arms of the yoke.

As previously mentioned, the feed rolls are urged toward the platen by springs l4, each of which is connected at one end to 8. lug 28 (Fig. 8) spot-welded on the cmss bar 3 and at the other end to its respective yoke arm 24 or 25, the springs serving to urge the yokes counterclockwise as viewed in Fig. 1. The tension of the springs may be adjusted very accurately and conveniently by a novel construction shown in detail in Fig. 8 in which one of the springs is shown, it being understood that the others are the same.

Referring to..Figure 8, the rear end of the spring I4 receives a threaded bushing 30 having external threads corresponding to the coils of the spring and a groove 3|'-by means of which the bushing may be threaded into the spring. This bushing is also provided with a threaded opening 32 (Fig. 8) which receives the threaded stem of an adjusting screw 33 that passes freely through and is supported by. the diagonally disposed lug 28. With this construction the screw 33 may be turned to increase or decrease the temsion of the spring. The heads of the screws 33 are placed inconvenient positions where they are readily accessible for quick adjustment. A very fine and accurate individual adjustment for each of thesprings l4 may thusbe obtained so that the feed rolls may be causedto engage theplaten with uniform pressure conditions throughout. This is very advantageous in that it enables the paper to feed accurately and uniformly and with even propelling pressure throughout thereby eliminating wrinkling. The accessibility of the adjustment is important in servicing the machines because it enables the pressure of the feed rolls to be quickly changed without disassembling the mechanism or changing any of the parts The operating rock shaft I5 is rotatably supported by being journaled at its ends in the plates 2 and by being'supported intermediate its ends by bearing brackets 40 carried by the cross bar 3. These bearing brackets perform the additional function of acting as limit stops for the feed roll shaft 2| and, for this purpose they have upstanding lugs or projections 4| on them which are in the path of shaft 2| as shown in Figs. 4 and 5 and which limit its downward movement. The shaft I5 is not directly connected to the yokes It for operating them but has collars 42 fixed to it between the side the respective yokes l3 and these collars have arms 46 rigid with them which bear against the bottom crop pieces 26 of such yokes. The collars 42 aid in spacing the arms 24-25 of the yokes and hold the yokes against end-wise movement on shaft IS.

The operating shaft I5 is controlled as previously mentioned, by a finger piece It (Fig. 1). This finger piece is pivoted at 43 on the right side plate 2 and its lower end is pivotally connected to-a link' 44 which, in turn, is pivoted to one end of an arm 45 fixed to the operating shaft I5. When the finger piece is pulled forward from the position of Fig. 1-, the toggle arms 24 and 25 of.

i5 in the same direction. The finger piece I5 is located behind the platen shaft 4 which serves as stop means to limit the forward movement of the finger piece It to a position slightly past dead center where it remains until manually released. As the finger piece is thus moved, the yokes iii are rocked clockwise and the rocker arms l2 are moved downwardly'to move both the rear and to further front feed rolls away from the platen. Pulling the finger piece It forward moves the toggle arms Iii-44 over center so that, when the finger piece is released, thefeed rolls. remain in the disengaged position to which they have been moved.

Additional or auxiliary supports are provided for the shaft 2| near the center thereof in order maintained accurately in axial alignment and that the pressure with which each roller engages the platen will be the same. These supports comprise rocker arms 50 somewhat similar to the rocker arms l2, but having their rear ends 5| bent downwardly (Fig. 3) so as to clear the rear feed roller ill. The front ends of the rocker arms 50 rotatably support the front feed roll shaft 2| near its center and each rocker arm is provided with a hub52 journaled on a. pin 53 carried by a yoke 54 similar to the yokes i3 heretofore described. The 'yokes 54 positioned under the lips of rearwardly extending brackets 51 fixed to the cross .bar 3. The urge of springs 55 tends to rock yokes 54 counterclockwise, as viewed in Fig. 1, and, as the rocker arms move upward, during the return move- 'ment of the finger piece IS, the studs 56 on their rear ends 5| limit on the brackets 51 which causes the rocker on their pivots 53 and urge the front feed roll shaft 2| toward the platen. Thefront feed roll shaft 2| has thus only relatively short spans that are supported and or flexing of the shaft such as might put the different feed rolls out of axial alignment or vary the relative pressure of them if the span between the supports were 'loiiger.

Fronnthe above it will be apparent that a feed roll m echanism has been provided which includes a rear feed roll extending substantially the full length of the platen in combination with a pmrality of front feed rolls supported by a single shaft. The rear feed roll shaft is sufficiently rigid so that uniform pressure on the platen will be maintained throughout and the front feed'rolls are maintained in axial alignment by reason of being mounted on a single shaft with the furtherprovision of having intermediate supportsfor said shaft. Uniformity of pressure is obtained by using a plurality of springs with the springs individually adjustable so that the pressure may be regulated very freely. The whole structure is made very rigid and,-at the same time, it is mad in an economical manner and it is combined such a way that it may be inexpensively serviced after the carriage has been assembled.

tion of guiding the paper about the platen, but it insure that the front feed rolls will be are also urged. counterclockwise by springs similar to the arms 50, 5| to swing clockwise this tends to prevent bending a curvature which is approximately that of the platen as illustrated in Fig. 3. Suitable openings are provided in the apron so that both the front and the rear feed roll may project through the apron into engagement with the platen. The rear edge of the apron is spaced slightly from the platen when the feed rrills are in engagement with the platen as shown in Fig. 3 so that'a work sheet may be inserted between the apron and the platen to be gripped by the feed rolls and platen when the latter is rotated. This rear edge also has an inclined portion 5| which acts as a guide to guide an inserted work sheet into position between the feed rolls and platen.

Extending downwardly from the rear end of the rearwardly bent portion 5|- of the apron'BO are brackets 62, one .of which is shown in Fig. 3. These brackets act as bearings for the rear feed roll shaft 20.

Whenthe feed rolls move downwardly from the position of Fig. 3 to that of Fig. 4, the rear end of the paper apron is carried downwardly with the rear feed roll shaft and more space is provided between the rear edge of the apron and the platen to enable a thick group of papers to be inserted.

The front edge of the paper apron is urged into engagement'with the platen for the purposeof holding the work sheets in position after they have been inserted, and the arrangement is such that this engagement is maintained while the feed rolls are out of feeding relation with the platen as illustrated in Fig. 4. The front edge of the apron is urged into engagement with the platen by a plurality of arms 63 which are fixed to collars 64 (Fig. 1) "journaled on the operating shaft l5 and held in position between set screw collars B5 and the bearing brackets 40 which support the shaft i5. The upper rear ends of these arms are provided with curved noses 56 (Fig. 5) that engage the bottom of the paper apron and the arms are urged counterclockwise by springs 61 connected at one end to hooked extensions 68 on the arms and at their other ends to retaining members 69 (Fig. 8) on the cross brace 3. The spring pressed arms 63 urge the front edge of the'paper apron into engagement with the platen with a light yielding engagement both when the platen is in as' is often "the case, the paper may be inserted around the platen while the feed rolls are in engagement therewith after which the feed rolls are moved away and the operator then slides and adjusts the paper to the proper position after which he returns the feed rolls toward the platen. In either case, if the apron should be 'away from the platen, the papers tend 'to drop away from the platen slightly after the operator releases them and before the feed rolls reengage them. As the feed rolls m""ve toward the platen they then tend to shift the japer and this often gets it out of accurate posi en. This difficulty is avoided in the presnt invention by'reasen of the fact that the front edge of the paper apron holds the papers in position after they have been adjusted by hand. The apron is urged yieldingly against the paper at all times, but without sufficient pressure to interfere with easy adjustment of the sheets by the operator. When the operator releases the sheets they remain in the position to which he has adjusted them and, as the feed rolls move toward the platen, they do not change the position of the sheets.

In this manner the paper apron performs two functions, that is, it acts as a guide for the work sheets as they move about the platen and it serves to hold the work sheets in position after they have been adjusted and while the feed rolls are moving into engagement with the platen.

At times the work may take the form of a stifi card and, unless prevented, the card may, while it is being inserted, move the paper apron 60 away from the. platen against the tension of springs 67. To provide against this contingency, limit stops have been provided for the paper apron so that it can move down only a limited extent. These stops are in the form of flanged sleeves l rotatably mounted upon the front feed roll shaft 2! and positioned beneath portions of the paper apron. The ends of these sleeves are of larger diameter than the body portions providing flanges of such size that, if the paper apron is moved down by the insertion of a stiff card, as shown in Fig. 5, the apron will limit against the flanged ends of the sleeves so as to retain the apron in position to cause the card to be bent and guided at such an angle that it will be guided between the front feed rolls and the platen.

Modified feed roll mechanism for wide carriage In certain instances where wide carriages are used, particularly over fifteen inches in width, there may be some tendency for the correspondingly widened feed roll mechanism to become disaligned and engage the platen with non-uniform pressure. An increasingnumber of springs corresponding to the springs 55 of Fig. 1 must be employed and a considerably greater force would be exerted on the cross bar 3 to which said springs would normally be attached. This might cause some distortion or bending of the bar and consequent lack of uniformity in pressure of the front feed rolls or possible disalignment of them. To avoid the possibility of difiiculty along this line, a modified form of feed roll mechanism (Figs. 6 and 7) has been provided for wide carriages.

This feed roll mechanism (Figs. 6 and 'l) includes a plurality of rear feed rolls 80 and a plurality of front feed rolls 8|. As illustrated, a pair of rear feed rolls and a pair of front feed rolls for each rear feed roll are preferably employed. Each rear feed roll is rotatably supported upon a single shaft 82 and each pair of front feed rolls is rotatably mounted upon a single shaft 83. Each rear feed roll shaft 82 and the aligned front feed roll shaft 83 are rotatably supported at .their ends bya pair of rocker arms 84 which are,'in turn, supported by yokes 85 urged counterclockwise to yieldably engage the feed rolls with the platen similarly to the yokes 13 of the form of Fig.1.

The yokes 85, instead of being urged toward the platen by means of springs connected to'short lever arms on the front ends of the yokes as in the form of Fig. 1, are urged directly toward the platen by means of springs 86 connected to the rear ends 81 of the yokes 85 and to a cross bar 88. The connections of these springs to the cross bar 88 are adjustable as shown in Fig. 8.

The cross bar 88 takes the form, preferably, of a very rigid angle bar and it is supported at its ends by the carriage end plates 89 with its horizontal leg 90'extending, preferably, rearwardly above the yokes 85.

This arrangement provides a much longer lever arm for the yoke-urging springs to work on and they are thus more efiective for a given strength of spring. It enables the use'of a minimum number of springs each of minimum strength which is of importance, particularly, in the use of quite wide carriages. The angle bar 88 is so stiif that flexing of the same is not caused by the springs.

A paper apron 9i similar to the apron 60 of the form of Fig. 1 may be employed, in which case a single apron is associated with both sets of front and rear feed rolls. Other than above described, this modified form of feed roll mechanism is substantially the same as that of Fig. 1.

Modified paper apron construction A modified form of paper apron is shown in Figs. 9 and 10 which is more particularly useful where it is not necessary to operate on a thick group of papers. In this modification the paper apron is entirely independent of the feed roll mechanism.

Referring to Figs. 9 and 10, the paper apron comprises a curved metal plate I00 similar to the one previously described and provided with a rear inclined portion H which assists at its ends to guide the papers between the platen and the rear feed roll. Instead of being mounted on the feed roll shaft, this apron has downwardly extending lugs I02 at each side supportingstuds 103 pivotally mounted in brackets I04 secured to the carriage back plate I05. The forward edge of the apron is yieldably urged against the platen by spring pressed arms I06 similar to the arms 63 previously described.

In this form, the paper apron remains in the position of Fig. 9 both while the feed rolls are engaged with the platen (as in Fig. 9) and when they are moved out of engagement (as in Fig. 10) The rear end of the apron is spaced from the platen sufiiciently to admit papers of reasonable thickness, but will not, of course, take such a large group as the construction of Figs. 1 to 5, inclusive.

It is to be understood that while the constructions shown are for purposes of illustration only and that variations may be made without departfeed roll shaft toward the platen, auxiliary means rotatably mounted on said rock shaft and urging the mid-portion of said shaft toward said platen,

and means for rocking said rock shaft to move said first means and feed rolls away from the platen.

2. In a typewriter, a rotatableplaten, a single rear feed roll shaft extending substantially throughout the length'of said platen, a single front feed roll shaft extending substantially throughout the length of sai'd platen, feed rolls carried by said shafts, common support means for said feed roll shafts urging the same toward said. platen and including a rock shaft and an intermediate supporting member rotatable on said rock shaft toward said platen only, similar auxiliary support means for said front roll shaft intermediate the ends only of the latter, means for rocking said rock shaft for moving said feed rolls away from said platen, means urging said support members of all said support means and said feed rolls toward said platen with a substantially uniform pressure between said rolls and said platen throughout, and means for adjusting said urging means to'provide uniform pressure between the feed rolls and platen throughout the length of said feed roll shafts.

3. In a typewriter, a rotatableplaten, a single rear feedroll shaft extending substantially throughout the length of said platen, a single front feed roll shaft extending substantially throughout the length of said platen, feed rolls carried by said-feed r'oll shafts, a rock shaft, com-' mon support means for said feed roll shafts rotatably mounted on saidrock shaft and urging said feed rolls toward-said platen, auxiliary supthe length of said feed roll shaft, and means for 45 port means for said front roll shaft rotatably mounted on saidrock shaft and disposed intermediate the ends of the latter only, and means for rocking said rock shaft to move said feed roll shafts and feed rolls away from said platen.

4. In feed roll mechanism for a typewriter, a front feed roll structure which includes a single shaft, a plurality of spaced feed rolls mounted on said shaft in axial alignment, means supporting and urging the end portions of said shaft into an operative position and including a rock shaft, supporting members rotatable upon. said rock shaft toward the operative position, and springs acting on said supporting members to effect yieldable rotation of said support members, similar means supporting and urging the portions of said Y shaft intermediate its end portions into an operatiye position, means for adjusting] aid springs to urge said feed rolls .into said operative position with a. substantially uniform pressure throughout rocking said rock shaft to ,move and'hold said feed rolls out of said operative position.

5. In a typewriter, a rotatable platen, a relatively large rear feed roll carried by a single shaft,

said feed roll being of a length substantially equal to that of said platen, a plurality of front feed rolls carried by a single shaft so that said front feed rolls are .in axial; alignment, supporting means, including a rock shaft and supporting members rotatable upon said rock shaft, for said feed rolls acting to support said feed roll shafts at the ends thereof, springs rotating said supporting members and rock shaft in a direction to urge said feed rolls 7 into engagement with said platen,

means including a device on said rock shaft engageable with said supporting members and a manually operable device directly connected with said rock shaft for rotating the latter in an opposite direction to move said supporting members against the urge of said springs to move said feed rolls away from said platen, auxiliary supporting means on said rock shaft for said front feed roll shaft only for supporting thesame intermediate its ends, separate springs urging said auxiliary supporting means in a direction to urge said feed rolls into engagement with said platen, and means for readily-and accurately. adjusting the tension of each of said springs.

6. In a typewriting machinefthe combination with a rotatable platen, of a continuous rear feed roll extending substantially throughout the length of said platen, a shaft supporting said rear roll,

a plurality of front feed rolls, a single shaft supporting said front rolls in end to end axial alignment, supports for the ends only of said shafts common to both said shafts, supports for the intermediateportions of said front roll shaft only,

a common control member rotatably carrying said supports, means simultaneously rotating all said supports yieldably toward said platen with uniform pressure, and means associated with said control member and engaged with said supports for moving the latter simultaneously away from the platen.

rock arms at the other end, means carried by said rock shaft and engaging said yoke members to rotate the latter in one direction,- and spring means for rotating said yoke members in the opposite direction and opposing movement of said yoke members by said rock shaft means.

8. A feed roll mechanism adapted to be operatively associated with the platen of a typewriting machine which comprises front and rear feed rolls, rocker arms carrying said rolls, a rock shaft for swinging said feed rolls toward and from the platen, and means supporting said feed rolls upon and operatively connecting them to said rock shaft comprising yoke members having spaced arms joined together intermediate their ends by a bridge element, means pivotally mounting said rocker arms between said yoke arms at one end, means for rotatably mounting the other ends of said yoke arms upon said rockshaft, means rigidly connected to said rock shaft and enga eable with said yoke bridge elements to effect movement ofsaid rolls away from the platen when said rock shaft is rotated in one direction, and spring means urging said yoke members rotatably upon said rock shaft toward the platen.

' 9. A feed roll mechanism adapted to be operatively associated with the platen of atypewriting machine which comprises front and rear feed rolls, rocker arms carrying said rolls, a rock shaft, and means for supporting said feed rolls upon said rock shaft rockable toward and from the platen which includes yoke members in the form of spaced apart arms rigidly joined together androtatably supported at one end by said rock shaft and rotatably supporting said rocker arms at their other end, means constantly urging said yoke membersin one direction to engage said rolls with the platen, and means fixed to said rock shaft for moving said yoke members in the opposite direction to release said rolls from the platen, and means for rocking said rock shaft to actuate said yoke member moving means.

10. A feed roll mechanism .adapted to be operatively associated with the platen of a typewriting machine which comprlses front and rear feed rolls, rocker arms carrying said rolls, a rock shaft for swinging said feed rolls toward and from the platen, and means forsupporting said rolls upon and to one side of said rock shaft including yoke members each having a pair of arms rigidly joined together in spaced relation,-

member also having its arms at the other end rotatably mounted upon said rock shaft, means on said rock shaft adapted to engage said yoke members when said rock shaft is rotated in one direction to mov said rolls away from the platen, hook elements projecting from the rock shaft ends of said yoke arms, and spring, members each fixedly supported at one end and engaged with one of said hook elements of one of said yoke members at its other end for constantly urging said yoke members rotatably around said rock shaft and toward the platen.

11. A feed roll mechanism adapted to be operatively associated with the platen of a typewriting machine which comprises front and rear feed rolls, rocker arms carrying said rolls, a rock shaft for swinging said feed rolls toward and from the .platen, and means for supporting said rolls upon said rock shaft including yoke members each having a pair of arms, each said rocker arm having a hub pivotally supported between the arms of one of said yoke members at one end thereof, yoke actuating members each having a hub fixed to said rock shaft between the arms of one of said yoke members and having a hub,- carried part adapted to engage and actuate said yoke member as said rock shaft is rotated in one direction to move said feed rolls away from the platen, and spring means engagedwith said yoke members opposing said latter movement and constantly urging said yoke members and rolls toward the platen.

12. ,Feed roll mechanism for a typewriting machine having a platen, which comprises a plurality of rolls mounted for simultaneous movement toward and away from the platen, and means for supporting and'moving said feed rolls which includes a rock shaft, rocker arms supporting said rolls, yoke members each consisting of a pair of arms rigidly connected togetherintermediate their ends by a bridge element and having said arms at one end mounted for free rotation upon said rock shaft, means for pivotally mounting said rocker arms upon the other ends of said yoke arms, respectively, members fixed to said rock shaft and having arms adapted to engage the yoke bridge elements of certain of said yoke members when said rock shaft is rotated in one direction, and spring means connected to said yoke members and opposing move: ment of the latter by said rock shaft. arms.

13. In a typewriting machine, the combination with a pair of side members, a cross bar joining said side members, and a platen rotatably mounted between said side members, of a rock shaft rotatably supported by said side members, a feed roll unit including shafts supporting feed rolls,

support means for said roll unit carried by said rock shaft for movement toward and from the platen, a plurality of spring means connected to said feed roll support means comparatively close to said rock shaft and also connected to said cross bar for constantly urging said feed rolls toward the platen, and brace members connected to said rock shaft and to said cross bar opposing distortion of said shaft and bar by the presure of. said spring means, said brace members having stop elements adapted to engage one of said feed roll shafts when said feed roll unit is moved away from the platen to limit movement 'of the feed roll unit away from the platen.

14. In a typewriting machine, the combination with a rotatable .platen, a rear roll, a shaft supporting said rear roll, a front roll, a single shaft supporting said front roll, rocker arms supporting only the ends of, and common to, both saidshafts, intermediate rocker arms connected at one end only to an intermediate portion of said front roll shaft, a rock shaft, support members rotatably carried by said rock shaft and rotatably supporting said rocker arms, fixed stop members, projections on said intermediate rocker arms and extended rearwardly beneath said stops, means connected to the several of said supports and urging the latter rotatably about said rock shaft to urge said rolls toward the platen, and means directly connected to said rock shaft for rocking it in one direction to permit movement of said supports and feed rolls toward the platen and for rocking said rock shaft in an opposite direction, and means connecting said rock shaft and supports when said rock shaft is moved in said opposite direction to move said feed rolls away from the platen, the arrangement being such that the feed rolls are moved uniformly toward and from the platen in all positions along the feed roll shaft.

15. In a typewriter, a rotatable platen, front and rear feed rolls movable into and out of engagement withsaid platen, a paper apron positioned beneath said platen, the. rear portion of said apron being spaced from said platen so as to guide work sheets between said platen and feed rolls, and means constantly urging the front portion of said paper apron into and holding it in engagement with said platen to hold inserted work sheets accurately in position while all said feed rolls are out of engagement with said platen and as said feed rolls are being moved into engagement with said platen.

- 16. In a'typewriter, a rotatable platen, front and rear feed rolls movable into and out of engagement with said platen, a paper apron positioned beneath said platen, the rear portion of said paper apron being spaced from said platen so as to guide inserted work sheets between said feed rolls and platen means including a rock shaft for moving all said feed rolls away from said platen and simultaneously moving the rear portion of said paper apron farther away from said platen, and means journaled on said rock shaft maintaining the front portion of said paper apron in yielding engagement with said platen both-while all said feed rolls are in engagement with said platen and while they are out of engagement, whereby said paper apron holds inserted work sheets in accurate position irrespective of the position of the feed rolls.

17. In a typewriting machine the combination with a rotatable platen, of a work feeding mech-- anism which comprises a rock shaft. feed rolls, shaft means supporting said feed rolls, means connecting said feed roll shaft means to said rock shaft for movement of the former toward and from the platen, a work-guiding apron pivotally supported at its rear edge only by said feed roll shaft means, and means carried by said rock shaft for yieldably pressing the forward edge of said apron against the adjacent surface of the platen.

18. In a typewriting machine, the combination with a rotatable platen, of a work feeding mechanism which comprises a rock shaft, a feed roll unit, means connecting said feed roll unit to said rock shaft for movement of the former toward and from the platen, a work-guiding apron supported at its'rear edge only by said feed roll unit, means for positively moving and holding said feed roll unit and the rear edge of ried by said rock shaft for yieldably pressing the forward edge of said apron against the adjacent surface of the platen in all positions of said feed ment with the platen in all positions of said rear roll shaft, and means for limiting yielding movemerit of the forward edge of said apron away from the platen underthe control of the work passing between it and the platen.

20. In a typewriting machine, the combination with a-rotatable platen, of a work feeding mechanism which comprises a rock shaft, a feed roll unit including a rear roll shaft, a front-roll shaft, means supporting said front andrear shafts upon said rock shaft for movement relative to the platen, a work-apron pivotally supported at its rear edge by said rear roll shaft, spring means on said rock shaft urging the forward free edge of said apron against the platen in all positions of said feed roll shafts, and means on said front roll shaft limiting yieldable movement of the forward edge of said apron away from the platen when the work is fed into the machine.

21. In a typewriting machine, the combination with a rotatable platen, of feed rolls engageable with the platen, a rock shaft, means connectingsaid feed rolls to said shaft for movement of the former relative to the platen, a workguiding apron beneath the platen and said feed rolls, means pivotally supporting the rear edge of said apron leaving its forward edge free, one or more arms having one end thereof rotatably mounted upon said rock shaft and its other end engageable with the bottom of said apron, and spring means engaging the shaft mounted end of each said arm ,f or yieldably urging said arms toward said apron to hold its forward edge portion constantly in operative position upon the platen in all positions of said feed rolls.

22. In a typewriting machine, the combination with a rotatable platen, of feedrolls engageable with the platen, a rock shaft,"means connecting said feed rolls' to said shaft for movement of the former relative to the platen, a work-guiding apron beneath the platen and said 'feed rolls,

a fixed pivotal support for the rear edge of said apron independent of said feed rolls whereby said rear edge is maintained in a fixed position relative to the platen, and means mounted and free- 1y rotatable upon said rock shaft for constantly urging the forward and free edge of said apron under tension against the platen in all positions of said feed rolls.

23. In a typewriting machine, the combination with a rotatable platen, of feed rolls engageable with the platen, a rock shaft, means connecting said feed rolls to said shaft for movement of the former relative to the platen, a workguiding apron beneath the platen and said feed roll unit, a fixed pivotal support for the rear edge of said apron independent of said feed rolls whereby said rear edge is maintained in a fixed position'relative to the platen, one or more arms mounted for free rotation upon said rock shaft,

and spring means constantly urging said arms against said apron to engage the latter with the platen in a yieldable manner in all positions of said feed rolls.

24. In a typewriter, a rotatable platen, feed rolls mounted beneath said platen, means for supporting said feed rolls for movement toward and from said platen which includes a rock shaft, support members rotatably mounted at one end upon said rock shaft and rockably connected to said feed rolls at the other end, said support members having rigid arms extending from the connections between said support members and said rolls and rearwardly of said platen, a nonflexible cross bar rigidly supported rearwardly of said platen and above said arms, and a spring connected to each said arm and adjustably connected to said cross bar directly and constantly pulling said arms and feed rolls up toward said platen. a

RAYMOND G. BOWER. DWIGHT P; ROWLAND. 

